A relatively new radiator has stopped working. The heat can be felt coming to the pipe connected to the radiator but does not seem to be able to pass in to the rad?
Seeing as this is a new rad, is it possible the thermostat on the radiator is faulty? and is it a big job to remove and replace??
All others in the house are O.K. and all have been bled.

I'm no plumber but this happened to me a couple of years ago with a new radiator - it just would not heat and when I tried to bleed it nothing came out of the bleed nipple, no air nor water. I then realised after playing for hours with the TRV and valve that the manufacturer had spray painted the radiator and this paint had formed a seal inside the bleed hole and by sticking a pin/paper clip in the hole breaking this paint seal voila everything worked.